The present invention relates generally to an anchoring device for fastening the base of a machine onto a foundation. More particularly, the invention is directed to the type of device which includes an anchor bolt movable in the axial direction.
When mounting machines in place, the connecting means which are located between the machine and the ground upon which the machine rests is the machine foundation which comprises the body upon which the machine is installed. In operation, machines generally produce variable forces of different types. These may include inertia forces, shocks or other effects due to the energy output of the machine, and irregularities in the movements of the machine. Such variable forces are conducted into the foundation and through the foundation into the ground upon which the machine rests. The function of the foundation is to operate as a supporting construction in order to, first of all, secure as accurately as possible the bearing shafts of coupled units and to maintain them in place. Additionally, these functions include the necessity for maintaining the machine set in as stable a manner as possible during its operation and to prevent, as far as possible, the effects of unavoidable interacting forces originating from the setting of the machine.
Machine foundations are frequently made of concrete.
Large machines are usually placed upon their foundations by rollers which enable the machine to be located by gliding movement thereof. This operation usually requires a planar foundation having no projecting parts in order not to impede movement of the machine during its placement at a desired position. It is not customary to place machines directly upon a concrete foundation but instead it is more usual to support them by suitable means such as bolts or the like.
In order to fasten a machine upon its foundation, foundation anchors are generally utilized which provide the function of securing the machine against horizontal and vertical displacement. Foundation anchors of the type referred to are described, for example, in German DOS No. 2,304,132.
Presently known foundation anchors require adherence to exact dimensional tolerances in their use. In order to effect such exacting dimensional requirements, elaborate calculations are necessary. Furthermore, it is usually necessary in the production of the foundation to provide large recesses. After such a foundation has hardened, the foundation anchors are inserted into these recesses and they are connected by struts in order to achieve a high degree of accuracy with regard to the dimensional factors involved. The cavities or recessess are filled with concrete and the hardening time of the concrete is usually in the neighborhood of about four weeks. The struts applied between the foundation anchors are removed after the concrete has set and hardened.
Despite the elaborate and time-consuming operations which must be performed, dimensional discrepancies in one or more of the foundation anchors can not be avoided. If one or another foundation anchor exhibits dimensional discrepancies, it then becomes necessary to repeat the application of the concrete and the start of the assembly is delayed by virtue of the hardening or setting time of the concrete.
It is an object of the present invention to provide a foundation anchor of the aforementioned type which does not involve the inconveniences inherent in known anchors and which may be used simultaneously with the production of the foundation.